Oracle to GCS
real-time replication
TwinCommit replicates Oracle Database to Google Cloud Storage in real time by reading the Oracle transaction log and applying every committed change exactly once and in commit order. Use it to land live Oracle data in GCS as open Delta Lake or Iceberg tables, with no triggers or capture tables on the source.
Oracle
log reader
commit-ordered · exactly-once
GCS
native writer
How capture works on Oracle
TwinCommit parses online redo and archived logs directly, including RAC threads, and reassembles transactions in SCN order before they leave the host.
Prerequisites
- ✓ARCHIVELOG mode
- ✓Minimal plus primary-key supplemental logging
- ✓Read access to V$ views and the archive destination
How apply works on GCS
Changes land as Apache Iceberg, Delta Lake or Parquet tables with one atomic commit per micro-batch. Iceberg tables register in the BigLake metastore so BigQuery can query them in place.
Requirements
- ✓Storage Object Admin on the bucket
- ✓BigLake Admin for catalog registration (optional)
- ✓Workload identity or a service-account key
Setup
Set up Oracle → GCS in four steps
- 1
Prepare Oracle
Run twincommit check. It verifies archivelog mode and the other prerequisites, and prints the exact fix for anything missing.
- 2
Point at GCS
Add a target block for GCS. TwinCommit can generate target DDL with twincommit ddl -apply.
- 3
Snapshot
twincommit snapshot copies each table under a brief share lock and records the exact log position.
- 4
Stream
twincommit run streams every committed change from that position, exactly once and in commit order.
source:
type: oracle
database: PRODDB
user: ${SRC_USER}
password: ${SRC_PASSWORD}
target:
type: gcs
bucket: acme-lake
path: replica/{schema}/{table}
format: iceberg
catalog: { type: biglake, project: acme-analytics }
tables:
- source: SALES.ORDERS
- source: SALES.ORDER_LINES
exclude_columns: [INTERNAL_NOTES]Oracle to GCS replication FAQ
How does TwinCommit replicate Oracle to GCS?
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TwinCommit reads changes from the Oracle transaction log, buffers them per transaction, and applies each committed transaction to GCS in commit order. Changes land as Apache Iceberg, Delta Lake or Parquet tables with one atomic commit per micro-batch. Iceberg tables register in the BigLake metastore so BigQuery can query them in place.
Does Oracle to GCS replication need triggers or capture tables?
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No. TwinCommit reads the Oracle log directly and creates no objects in the source database.
Is Oracle to GCS replication exactly-once?
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Yes. TwinCommit commits its checkpoint in the same GCS transaction as the data, so a crash or restart never loses or duplicates a transaction.
What Oracle versions are supported?
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Oracle 19c, 21c, 23ai · RAC, Data Guard standby, CDB/PDB · Autonomous Database (target).
Stream Oracle to GCS today.
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